The car's performance is enhanced with the optional Performance Package that adds Bilstein electronic adjustable shock absorbers, a Torsen limited-slip differential and a Brembo brake package. Ford says the 2013 Shelby GT500 convertible with the Performance Package is nearly 3.5 seconds faster around Sebring International Raceway than the 2012 model.

The driver can choose between normal and sport modes for the suspension. Normal mode softens the ride for more comfortable cruising.

Other equipment in the Shelby GT500 convertible includes driver-adjustable steering effort and launch control programming for the powertrain. The car's supercharged V8 is mated to a six-speed manual transmission.

Ford is also using the debut of the Shelby GT500 convertible to celebrate the 20th anniversary of the SVT performance group. The Mustang Shelby GT500 convertible gets lighted sill plates with a commemorative emblem. Ford's Special Vehicle Team has helped produce more than 210,000 vehicles in its two decades.

SVT now works with Ford's RS team in Europe to develop high-performance versions of Ford vehicles. The groups collaborated to create the forthcoming Focus ST and Fiesta ST.